1. Field of the Invention
This invention relates to non-destructive test-instruments and, in particular, to magnetizing devices for magnetographic inspection, and is intended for magnetic recording of flaw fields during magnetographic inspection, for example, during weld inspection.
2. Description of the Prior Art
Known in the art is a device for magnetographic inspection, comprising a U-shaped two-pole electromagnet equipped with four rollers set in pairs on the poles of the electromagnet and two guides, each guide interacting with a respective pair of rollers. The guides are usually the surface of the inspected object, for example, during the inspection of welds it is the surface of the welded plates. As the magnetizing device is moved from one inspection zone to another it has to overcome numerous obstacles, such as irregularities of the surface, solidified metal splashes on the plate surface, misalignment of the plates, loose welding flux, etc. The precision of movement along inspection zones is also impaired. Moreover, when the device has to be transported over a corrugated or some other similar surface where the size of irregularities is comparable to the diameter of the rollers, the movement becomes extremely difficult if not impossible, considering the weight of the electromagnetic device (cf., for example, the USSR Inventor's Certificate No. 315,112, IPC G OI n 27/82 published in 1971).